Renal Protective Role Research Articles

Cardiac and Renal Protective Role of Erythropoietin in a Rat Model of Acute Myocardial Infarction

Background: Acute kidney injury is of a high prevalence rate in acute myocardial infarction (AMI) patients. Erythropoietin (EPO) protects tissues from ischemia. Aim of the study: To investigate the possible cardiac and renal protective effects of EPO in a rat model of AMI and their mechanisms. Materials and Methods: 27 male adult albino rats were divided randomly and equally into 3 groups [control, myocardial infarction (MI) and MI pre-treated with EPO]. In control and MI groups, 2 ml saline were injected subcutaneously once every other day for 7 days. In MI pretreated with EPO group, rats were injected subcutaneously with EPO 1000 IU/kg once every other day for 7 days. In the 6th and 7th days, rats in MI and MI pretreated with EPO groups were injected subcutaneously with isoproterenol (ISO) hydrochloride (150 mg/kg body weight /day), to induce MI. 1hr after the 2nd dose of ISO, ECG was recorded. Serum was separated from collected blood at the end of experiment for measurement of creatinine, TNF-α, MDA, LDH, IL-6, GSH and CK-MB. Cardiac and renal immunohistochemical study was done.Results: In MI group, increased cardiac and renal Bax immunostaining and increased serum level; of LDH, CK-MB, creatinine, IL-6, MDA and TNF-α were noticed, with a significant reduction in serum GSH in comparison with control group. In MI pretreated with EPO group, these changes were ameliorated.Conclusion: Erythropoietin has cardiac and renal protective effects in a rat model of AMI which could be owed to its antioxidant, anti-inflammatory and antiapoptotic roles.

Pectin-Lyase-Modified Ginseng Extract and Ginsenoside Rd Inhibits High Glucose-Induced ROS Production in Mesangial Cells and Prevents Renal Dysfunction in db/db Mice.

Diabetes increases the incidence rate of chronic renal disease. Pectin-lyase-modified ginseng (GS-E3D), with enhanced ginsenoside Rd content, has been newly developed. In this study, renal protective roles of GS-E3D in type-2 diabetic db/db mice were investigated. The generation of reactive oxygen species (ROS) induced by high glucose (25 mM) was reduced by ES-E3D (75%) and ginsenoside Rd (60%). Diabetic db/db mice received 100 or 250 mg/kg/day of GS-E3D daily via oral gavage for 6 weeks. Albuminuria and urinary 8-hydroxy-2′-deoxyguanosine (8-OhdG, an oxidative stress marker) levels were increased in db/db mice and the levels recovered after GS-E3D treatment. In renal tissues, TUNEL-positive cells were decreased after GS-E3D treatment, and the increased apoptosis-related protein expressions were restored after GS-E3D treatment. Therefore, GS-E3D has a potent protective role in diabetes-induced renal dysfunction through antioxidative and antiapoptotic activities. These results may help patients to select a dietary supplement for diabetes when experiencing renal dysfunction.

Nephroprotective effect of coadministration of curcumin and sildenafil in adenine-induced chronic renal failure in rats

BackgroundChronic renal failure (CRF) is a major public health problem worldwide. The pathophysiological basis of the disease and its complication include inflammation and oxidative stress, which are similar in humans and animals. In this study, we seek to develop new therapeutic modalities for CRF.ObjectiveThis study aimed to investigate the nephroprotective effects of curcumin (CUR) and/or sildenafil in adenine (AD) model of CRF.Materials and methodsRats were divided into five groups as follows: control naive group, AD group received AD 200 mg/kg/day orally to induce CRF, CUR group received CUR 200 mg/kg/day in addition to AD, sildenafil group received sildenafil 0.5 mg/kg/day in addition to AD, and combination group received combination of CUR 200 mg/kg/day and sildenafil 0.5 mg/kg/day in addition to AD. After consecutive 28 days of treatment, body weight, kidney index, and Doppler on renal artery assessments were done for all groups. In addition, kidney function tests and markers of oxidative stress were evaluated. Histopathological assessment of renal tissues and immunohistochemical staining for tumor necrosis factor-α were performed.ResultsCUR, sildenafil, and their combination significantly decreased body weight loss and urine volume and improved renal hemodynamic changes caused by AD. In addition, they significantly improved kidney function tests and biomarkers of oxidative stress. A significant down-regulation of tumor necrosis factor-α immunohistochemical expression was noted. They also brought histopathological changes induced by AD toward normal.ConclusionCUR and sildenafil may play a role in renal protection in AD-induced nephrotoxicity. The combined treatment showed better nephroprotective effect than either treatment alone did.

Nephroprotection through Modifying the Apoptotic TNF-α/ERK1/2/Bax Signaling Pathway and Oxidative Stress by Long-term Sodium Hydrosulfide Administration in Ovalbumin-induced Chronic Asthma

ABSTRACT Asthma is one of the most common respiratory diseases in the world. Nevertheless, it is reported that inflammation induced by asthma is not only restricted to the lung and may cause damaging effects on remote organs. Therefore, this study was designed to investigate the beneficial effects of long-term sodium hydrosulfide (NaHS) administration on lung inflammation and oxidative stress markers to protect the kidney during chronic asthma. BALB/c mice were divided into three groups (n = 5–7): control, asthma and NaHS. Except the control group, sensitization and challenge were performed with ovalbumin. The NaHS group intraperitoneally received 14 μmol/kg NaHS 30 min before each challenge. 24 h after the last challenge, samples of bronchoalveolar lavage fluid (BALF), plasma, lung and kidney tissues were collected. NaHS administration significantly decreased total white blood cell count, percentages of eosinophils, neutrophils and macrophages and increased percentage of lymphocytes. Administration of NaHS considerably decreased the levels of BALF interleukin-13, plasma tumor necrosis factor-alpha (TNF-α), lung malondialdehyde (MDA) and lung phosphorylated nuclear factor-kappa B (p-NF-κB) expression and scores of peribronchial inflammatory cell infiltration, goblet cell hyperplasia and subepithelial fibrosis and increased the activity of lung superoxide dismutase (SOD). The MDA levels and expressions of p-ERK1/2 and Bax were decreased and SOD activity and expressions of Bcl-2 and p-Akt were significantly increased in kidney tissues by NaHS administration. Administration of NaHS decreased renal oxidative stress indices and reduced apoptosis by the inhibition of TNF-α/ERK1/2/Bax. Therefore, H2S may have an essential role in renal protection during asthma.

Protective role of DJ-1 in endotoxin-induced acute kidney injury.

Acute kidney injury (AKI) is a frequent complication of sepsis and an important cause of morbidity and mortality worldwide. A cornerstone of sepsis-associated AKI is dysregulated inflammation, leading to increased tissue oxidative stress and free radical formation, which leads to multiple forms of cell death. DJ-1 is a peroxiredoxin protein with multiple functions, including its ability to control cellular oxidative stress. Although DJ-1 is expressed prominently by renal tubules, its role in AKI has not been investigated. In the present study, we examined the effect of DJ-1 deficiency in a murine model of endotoxin-induced AKI. Endotoxemia induced greater kidney injury in DJ-1-deficient mice. Furthermore, DJ-1 deficiency increased renal oxidative stress associated with increased renal tubular apoptosis and with expression of death domain-associated protein (DAXX). Similar to the in vivo model, in vitro experiments using a medullary collecting duct cell line (mIMCD3) and cytotoxic serum showed that serum obtained from wild-type mice resulted in increased expression of s100A8/s100A9, DAXX, and apoptosis in DJ-1-deficient mIMCD3 cells. Our findings demonstrate a novel renal protective role for renal tubular DJ-1 during endotoxemia through control of oxidative stress, renal inflammation, and DAXX-dependent apoptosis.

Aminophylline for renal protection in neonatal hypoxic-ischemic encephalopathy in the era of therapeutic hypothermia.

Background:Neonates with hypoxic ischemic encephalopathy (HIE) frequently develop acute kidney injury (AKI). Aminophylline has been shown to reduce severe renal dysfunction in neonates after perinatal asphyxia. However, the effect of aminophylline on renal function in neonates undergoing hypothermia has not been studied.Methods:A single-center, retrospective chart review of neonates cooled for moderate/severe HIE who received aminophylline for AKI was conducted to assess changes in urine output (UOP) and serum creatinine (SCr). Comparisons were also made to control neonates matched for hours of life who were cooled but unexposed to aminophylline.Results:Sixteen neonates cooled for HIE received aminophylline starting at 25 ± 14 hours of life. Within 12 hours of starting aminophylline, UOP increased by 2.6 ± 1.9 ml/kg/h. SCr declined by 0.4 ± 0.2 mg/dl in survivors over the first 4 days. When compared to control neonates, UOP increase was greater in the aminophylline group (p<0.001). SCr declined in survivors in both groups, although baseline SCr was higher in the aminophylline group.Conclusion:Aminophylline use in neonates with HIE undergoing hypothermia was associated with an increase in UOP and a decline in SCr. A randomized trial will be needed to establish a potential renal protective role of aminophylline.

Protective effect of renal ischemic postconditioning in renal ischemic-reperfusion injury.

BackgroundRenal ischemic postconditioning (RIPo) can protect the kidney from renal ischemia/reperfusion injury (RIRI). However, the underlying molecular mechanisms for RIPo in renal protection remained elusive. This study aimed to investigate the renoprotective effects of RIPo in an RIR rat model.MethodThe Sprague Dawley (SD) rats were randomly divided into three groups respectively: sham group, the RIRI group and the RIPo group. The levels of proteinuria, blood urea nitrogen (BUN), creatinine (Cr), malondialdehyde (MDA), superoxide dismutase (SOD), lactate dehydrogenase (LDH), reactive oxidative species (ROS), interleukins (IL)-6, IL-1β, and IL-18 were measured by ELISA. Apoptotic cells and caspase-3 positive cells were detected by TUNEL assay and immunohistochemistry, respectively. The protein expressive levels of caspase-3, caspase-9, ATG8, Beclin1, p62, LC3-II, P-P13K, P-AKT and P-mTOR were detected by western blot.ResultsOur results showed that pretreatment with RIPo significantly reduced ischemic pathological and morphological changes. The levels of proteinuria, BUN, and Cr were also significantly reduced by RIPo pretreatment. Besides, ATG8, LC3-II and Beclin-1 were upregulated in the RIPo group, but p62 was downregulated. Moreover, RIPo pretreatment resulted in higher levels of phosphorylated PI3K, Akt, and mTOR. These results showed that RIPo protects the kidneys of rats from IRI with suppressed apoptosis and activated autophagy. Mechanically, the activated PI3K/AKT/mTOR signaling pathway were activated.ConclusionsCollectively, our data demonstrated that RIPo could suppress Inflammatory response, oxidative stress, apoptosis and induce autophagy as well as activate the PI3K/AKT/mTOR pathway, which may play an important role in renal protection against RIRI.

The Effect of Glucagon-Like Peptide-1 Receptor Agonists on Renal Outcomes in Type 2 Diabetes.

This review examines the available literature on the effect of glucagon-like peptide-1 receptor agonists (GLP-1RAs) on renal outcomes in type 2 diabetes mellitus. Diabetes is an important cause of end-stage renal disease requiring renal replacement therapy, and diabetic kidney disease is an independent risk factor for cardiovascular disease (CVD). GLP-1RAs are proven to be safe in terms of CVD, and some of them have been shown to have a beneficial effect on cardiovascular outcomes. The effect of GLP-1RAs on hard renal endpoints has yet to be established; to date, there have been no published GLP-1RA clinical trials with primary renal endpoints. In this review, we discuss the evidence for a renal protective role of GLP-1RAs, highlighting the secondary renal outcomes from recent cardiovascular outcome trials of this class of glucose-lowering therapies.

Renal physiology of glucose handling and therapeutic implications.

The rationale for using sodium-glucose cotransporter 2 (SGLT2) inhibitors in patients with type 2 diabetes (T2D) has evolved over the last decade. Due to the effects on glucosuria and body weight loss, SGLT2 inhibitors were originally approved for glycemic control in T2D. Since glucosuria is attenuated in chronic kidney disease (CKD) Stages 3–5, initial regulatory approval for SGLT2 inhibitor use was limited to patients with T2D and preserved estimated glomerular filtration rate. Over time, however, it has become increasingly apparent that these therapies have a variety of important pharmacodynamic and clinical effects beyond glycemic lowering, including antihypertensive and antialbuminuric properties, and the ability to reduce glomerular hypertension. Importantly, these sodium-related effects are preserved across CKD stages, despite attenuated glycemic effects, which are lost at CKD Stage 4. With the completion of cardiovascular (CV) outcome safety trials—EMPA-REG OUTCOME, CANVAS Program and DECLARE TIMI-58—in addition to reductions in CV events, SGLT2 inhibition consistently reduces hard renal endpoints. Importantly, these CV and renal effects are independent of glycemic control. Subsequent data from the recent CREDENCE trial—the first dedicated renal protection trial with SGLT-2 inhibition—demonstrated renal and CV benefits in albuminuric T2D patients, pivotal results that have expanded the clinical importance of these therapies. Ongoing trials will ultimately determine whether SGLT2 inhibition will have a role in renal protection in other clinical settings, including nondiabetic CKD and type 1 diabetes.

Renin angiotensin system blockage by losartan neutralize hypercholesterolemia-induced inflammatory and oxidative injuries

ABSTRACT Objectives: This study explores the protective role of losartan (LT) against oxidative and inflammatory damages in different physiological systems including heart, liver, and kidney tissue in hypercholesterolemic rats. Methods: After induction of hypercholesterolemia by high cholesterol diet for 6 weeks, LT was administered for 4 weeks. In serum, the levels of lipoproteins, aminotransferases, creatine kinases, urea, apoptosis, and inflammatory markers were measured. In cardiac, hepatic, and renal tissues, lipid peroxidation product and GSH as well as antioxidant enzymatic activities were assayed. Finally, histopathological assessment evaluated the structural damage in cardiac, hepatic, and renal tissues. Results: Serum markers of cardiac, hepatic, and renal toxicities including creatine kinases, aminotransferases, and urea were attenuated by LT in hypercholesterolemic animals. Moreover, LT markedly corrected the elevated levels of lipoproteins, apoptosis, and inflammatory biomarkers. Hypercholesterolemia-induced lipid peroxidation, low GSH levels, and diminished activities of antioxidant enzymes were prominently improved in LT treated animals. Histopathological alterations by hypercholesterolemia in heart, liver, and kidney tissues were ameliorated by LT. Conclusion: This study confirmed the pathological enrollment of renin–angiotensin system in hypercholesterolemia-associated metabolic alterations. LT had a significant cardiac, hepatic, and renal protective role against these impairments through down-regulation of oxidative damage, inflammation and necrosis.

Phloretin ameliorates hyperuricemia-induced chronic renal dysfunction through inhibiting NLRP3 inflammasome and uric acid reabsorption

BackgroundHyperuricemia (HUA) is an important risk factor for renal diseases and contributes to renal fibrosis. It has been proved that phloretin has antioxidant and anti-inflammatory properties and could inhibit uric acid (UA) uptake in vitro. However, whether phloretin has a renal protective role in vivo remains unknown. PurposeThis study aims to evaluate the therapeutic effect of phloretin on HUA-induced renal injury in mice and to reveal its underlying mechanism. MethodsMice were induced hyperuricemic by oral gavage of adenine/potassium oxonate. The effects of phloretin on renal function, fibrosis, oxidative stress, inflammation, and UA metabolism in HUA mice were evaluated. The effect of phloretin on NLRP3 pathway was analyzed in human renal tubular cell lines (HK-2). ResultsHUA mice showed renal dysfunction with increased renal fibrosis, inflammation and mitochondrial stress. By contrast, phloretin reduced the level of serum blood urea nitrogen (BUN), urinary albumin to creatinine ratio (UACR), tubular necrosis, extracellular matrix (ECM) deposition and interstitial fibroblasts in HUA mice. The renal infiltration of inflammatory cells, cytokines such as NOD-like receptor family pyrin domain containing 3 (NLRP3) and interleukin-1β (IL-1β) release, mitochondrial reactive oxygen species (ROS) and morphological lesions in HUA mice also decreased. Furthermore, phloretin partly inhibited renal glucose transporter 9 (GLUT9) and promoted urinary UA excretion in HUA mice. In vitro, phloretin suppressed the NLPR3 pathway under LPS or UA stimulation in HK-2 cells. ConclusionsPhloretin could effectively attenuate UA-induced renal injury via co-inhibiting NLRP3 and UA reabsorption, and thus it might be a potential therapy to hyperuricemia-related renal diseases.

26-LB: Systemic Inhibition of MicroRNA-451 Impairs Renal Autophagy Process in a Mouse Model of Insulin Resistance and Early Diabetic Nephropathy

Diabetic nephropathy (DN) is a severe complication of diabetes mellitus and a common cause of end stage renal disease (ESRD). Novel effective therapies are needed to combat disease progression. Several studies suggest a renal protective role of microRNA-451 (miR-451) in ameliorating progression of DN. However, the role of miR-451 in DN is not understood. Defects in the autophagy process has been associated with DN. The current study aimed to elucidate the role of miR-451 in the development of DN in a mouse model of insulin resistance. Male TALLYHO/Jng mice were placed on a high-fat diet (60% kCal) and divided into two treatment groups. Mice were injected (intraperitoneal) once a week for 8-weeks with locked nucleic acid (LNA) miR-451 inhibitor or LNA-scramble (2mg/kg/bw; n=8/treatment). Mice were humanely euthanized after 12 weeks and kidneys harvested. LNA-miR-451 inhibitor significantly reduced renal expression of miR-451 by 6-fold. Collagen deposition was higher in inhibitor treated mice, as revealed by Masson’s Trichrome. Period Acid Schiff did not reveal significant glomerular damage between the two groups. Kidney weight (normalized to body weight) was significantly higher in the inhibitor treated mice. Western blotting analyses of cortex homogenates revealed increased expression of markers of renal injury, KIM1 and NGAL (p&amp;lt;0.05), in inhibitor treated mice. The expression of fibrotic signaling molecules mTOR, AMPKα, and TGF-β was significantly higher in the inhibitor treated group. The expression of autophagy markers SQSTM1/p62 and Beclin-1 was higher and lower, respectively, in inhibitor treated mice (p&amp;lt;0.05). The findings of this study suggest that reduced expression of miR-451 in DN impairs autophagy response in the kidney possibly via hyperactivation of the mTOR-signaling pathway. miR-451 may confer protection against DN by targeting key components of the autophagy process in the diabetic kidney. Disclosure M.B. Fluitt: None. N. Shivapurkar: None. L. Li: None. C.M. Ecelbarger: None. Funding American Diabetes Association (1-18-PMF-002 to M.B.F.); National Institutes of Health (TL1TR001431)

SRT1720 retards renal fibrosis via inhibition of HIF1α /GLUT1 in diabetic nephropathy.

Renal fibrosis is a major pathological characteristic of diabetic nephropathy (DN). Reportedly, increased SIRT1 expression played a renal protective role in animal models of DN. This study was designed to elucidate the molecular mechanisms underlying the protective effects of SRT1720, an SIRT1 activator, against diabetes-induced renal fibrosis. Type 2 diabetic mice (db/db) were treated with SRT1720 (50 mg/kg/d) by gavage for 10 weeks. Renal proximal tubular epithelial cells (HK-2 cells) were treated with high glucose (HG, 30 mM) in the presence or absence of SRT1720 (2.5 µM) for 48 h. We observed that impaired SIRT1 expression and activity were restored by SRT1720 administration in db/db mice as well as in HG-treated HK-2 cells. Moreover, SRT1720 administration improved renal function, attenuated glomerular hypertrophy, mesangial expansion, glomerulosclerosis and interstitial fibrosis, and inhibited TGFB1 and CTGF expressions and nuclear factor κB (NF-κB) activation in db/db mice. Similarly, HG-induced epithelial-to-mesenchymal transformation (EMT), and collagen IV and fibronectin expressions were inhibited in SRT1720 treated HK-2 cells. Mechanistic studies demonstrated that SRT1720 suppressed HIF1α, GLUT1 and SNAIL expressions both in vivo and in vitro. Furthermore, Hif1α or Glut1 knockdown effectively abrogated HG-induced EMT and collagen IV and fibronectin expressions in HK-2 cells. These findings suggest that SRT1720 prevented diabetes-induced renal fibrosis via the SIRT1/HIF1α/GLUT1/SNAIL pathway.

REMOTE ISCHEMIC PRECONDITIONING, A NOVEL RENOPROTECTIVE STRATEGY AGAINST CONTRAST INDUCED ACUTE KIDNEY INJURY

Objective: To compare contrast induced Acute Kidney Injury amongst patientswith stable angina, unstable angina and Non ST elevation myocardial infarctionundergoing elective Coronary angiography and or percutaneous coronaryintervention with versus without applying Remote Ischemia Preconditioning. Methodology: It is a randomized control trial conducted at The Aga KhanUniversity Hospital, Karachi, from January, 2015 till June, 2015.Patients agedÝ30 years, having baseline serum creatinine level Ý 1.4mg/dl with the abovementioned conditions who were to undergo coronary angiography and orpercutaneous coronary intervention were randomly assigned to one of eitherintervention group or control group. All patients received standard care followedby application of RIPC to the intervention arm only. Baseline characteristics of allpatients were recorded and they were followed for 48 hours. The data wasanalyzed using STATA version 12.0. Results: Out of 103 patients, 53 were in Intervention arm and 50 in Control armwith an average age 65 and 66 years respectively. Majority were male in both thegroups. The primary outcome (Contrast Induced Nephropathy) was significantlylower in the intervention arm vs control arm (3.7% vs14%). Multivariable logisticregression analysis suggested a protective effect of the intervention (RIPC) withadjusted Odd Ratio of 0.07 (95% CI: 0.007-0.72, p-value: 0.026) Patients withprior MI were at higher risk for CI-AKI. Conclusion: Remote Ischemic Preconditioning has a significantly higher renalprotective role against Contrast Induced Nephropathy. Key Words: Remote ischemic preconditioning; Contrast induced acute kidneyinjury; Coronary angiography; Percutaneous coronary intervention; Acute renalfailure; Biochemical messengers, Oxidative stress

Obesity and chronic kidney disease progression-the role of a new adipocytokine: C1q/tumour necrosis factor-related protein-1.

BackgroundObesity is a risk factor for incident chronic kidney disease (CKD) in the general population. C1q/tumour necrosis factor-related protein 1 (CTRP1) is a new adipokine with multiple vascular and metabolic effects and may modulate the association between obesity and vascular diseases. The aim of the study is to explore potential links between obesity, CTRP1 levels and CKD progression.MethodsPatients with Stages 3 and 4 CKD without previous cardiovascular events were enrolled and divided into two groups according to body mass index (BMI). Demographic, clinical and analytical data and CTRP1 levels were collected at baseline. During follow-up, renal events [defined as dialysis initiation, serum creatinine doubling or a 50% decrease in estimated glomerular filtration rate (Modification of Diet in Renal Disease)] were registered.ResultsA total of 71 patients with CKD were divided into two groups: 25 obese (BMI >30 kg/m2) and 46 non-obese. CTRP1 in plasma at baseline was higher in obese patients [median (interquartile range) 360 (148) versus 288 (188) ng/mL, P = 0.041]. No significant association was found between CTRP1 levels and CKD stage, presence of diabetes, aldosterone and renin levels, or blood pressure. Obese patients had higher systolic blood pressure (P = 0.018) and higher high-sensitivity C-reactive protein (P = 0.019) and uric acid (P = 0.003) levels, without significant differences in the percentage of diabetic patients or albuminuria. During a mean follow-up of 65 months, 14 patients had a renal event. Patients with CTRP1 in the lowest tertile had more renal events, both in the overall sample (log rank: 5.810, P = 0.016) and among obese patients (log rank: 5.405, P = 0.020). Higher CTRP1 levels were associated with slower renal progression (hazard ratio 0.992, 95% confidence interval 0.986–0.998; P = 0.001) in a model adjusted for obesity, aspirin, albuminuria and renal function.ConclusionsCTRP1 levels are higher in obese than in non-obese patients with CKD. High CTRP1 levels may have a renal protective role since they were associated with slower kidney disease progression. Interventional studies are needed to explore this hypothesis.

Sema 3A as a biomarker of the activated mTOR pathway during hexavalent chromium-induced acute kidney injury

Semaphorin 3A (sema 3A) is one of a class of secretory proteins belonging to a family of axon-directed factors found in podocytes, distal tubules, and collecting tubes of the kidney. It is considered to be a potential target molecule involved in the mammalian target of the rapamycin (mTOR) pathway in renal injury or renal diseases, but it has an unknown role in the course of hexavalent chromium-Cr(VI) induced nephrotoxicity. In the present study, an acute kidney injury (AKI) model in rats or cultured tubular epithelial HK-2 cells was employed for Cr(VI) exposure alone or in combination with rapamycin (Rap) or N-acetyl-l-cysteine (NAC) or recombinant sema 3A. The methods of histopathology, biochemics, and western blotting were applied to evaluate tubular injury and the role of sema 3A. The results showed that a significant increase of urinary sema 3A indicates an early occurrence of AKI exposed to Cr(VI), accompanied with a significant increase of tubular injury score and phosphorylated mTOR proteins. Further, Cr(VI) treatment, in combination with pretreatment of the mTOR pathway inhibitor, Rap, showed a considerably stronger protective effect of Rap in protecting against Cr(VI)-induced nephrotoxicity than that seen with the free radical scavenger NAC, highlighting the dominant renal protective role of the mTOR pathway in inhibiting toxicity by downregulating the expressed levels of sema 3A in renal tissue. This study has demonstrated that an increased expression of sema 3A occurs in Cr(VI)-induced AKI resulting from activation of the mTOR pathway, and that inhibition of this pathway has been shown to decrease the severity of the toxicity. In conclusion, this study has shown that increased urinary sema 3A is indicative of an activated mTOR pathway and is a valuable biomarker of the early AKI induced by Cr(VI) exposure.

BAPTA-AM Nanoparticle for the Curing of Acute Kidney Injury Induced by Ischemia/Reperfusion.

Ischemia-reperfusion (I/R) is a major cause of acute kidney injury (AKI), which is associated with unacceptably high mortality rates in ICU. This research was designed to explore the therapeutic effect of BAPTA-AM (1,2-Bis(2-aminophenoxy) ethane-N,N,N,N-tetraacetic acid tetrakis(acetoxymethyl ester)) nanoparticle (BA-N) on AKI. BA-N was developed by liposome strategy and characterized by standard methods. The rat model was selected and the rats were randomly allocated into four groups: (1) Normal group; (2) Sham-operated group; (3) Model group (I/R + NS); (4) BA-N treatment group (I/R + BA-N). AKI model was established via clipping the bilateral renal artery with a microvascular clamp for 45 min. After reperfusion, serum cystatin C (Cys C), creatinine (Cr), blood urea nitrogen (BUN), lactate dehydrogenase (LDH) and caspase 3 levels were determined for the assessment of renal function. Kidney samples were then collected for the measurement of renal malondialdehyde (MDA) level and superoxide dismutase (SOD) activity. The assays of histological examination, ELISA, immunohistochemistry, western blot, TUNEL and RT-PCR were utilized for the detection of apoptosis. The results demonstrated that AKI model caused a significant decreasing in SOD activity, accompanied by a remarkable increase in Cys C, Cr, BUN, LDH, MDA, caspase 3 and cytochrome c (Cyt C) level, compared to the control group. BA-N (100 μg/kg i.v.) significantly improved renal function and histopathological appearance, restored MDA level and SOD activity, decreased Bax/Bcl-2 ratio, caspase 3 activity, Cyt C release and TUNEL positive apoptotic cells. Our studies indicated that BA-N plays a renal-protective role, probably through antiapoptotic and antioxidant mechanisms. BA-N may regulate mitochondria pathway via decreasing Bax/Bcl-2 ratio, inhibiting caspase 3 expression and Cyt C release. Overall, BA-N may have potentials as an anti-AKI drug.

Cardiovascular and renal protective role of angiotensin blockade in hypertension with advanced CKD: a subgroup analysis of ATTEMPT-CVD randomized trial

The ATTEMPT-CVD study was prospective randomized active-controlled trial and the main findings had been reported. According to baseline GFR and albuminuria categories, we divided the patients of the ATTEMPT-CVD study into 2 subgroups: (Group 1) the patients with at least one of eGFR of <45 ml/min per 1.73 m2 and UACR of ≥300 mg/g creatinine, defined as G3b and/or A3; (Group 2) the patients except for Group 1, defined as the other patients. In patients with G3b and/or A3, the incidence of cardiovascular events was significantly less in ARB group than in non-ARB group (11 vs 22, respectively) (HR = 0.465: 95%CI = 0.224–0.965; P = 0.040). UACR was significantly less in ARB group than in non-ARB group during follow-up period in patients with G3b and/or A3 (P = 0.0003), while eGFR, plasma BNP levels, and blood pressure were comparable between ARB and non-ARB groups. Allocation to ARB therapy was a significant independent prognostic factor for cardiovascular events in patients with G3b and/or A3 (P = 0.0268). On the other hand, in the other patients, the occurrence of cardiovascular events was comparable between ARB and non-ARB groups. In patients with advanced CKD, ARB-based therapy may confer greater benefit in prevention of cardiovascular events than non-ARB therapy.

Nrf2 deficiency promotes the progression from acute tubular damage to chronic renal fibrosis following unilateral ureteral obstruction.

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a central mediator of cellular responses to oxidative stress. We hypothesized that Nrf2 modulates progression from acute tubular damage to renal fibrosis. We asked whether Nrf2 deletion increases renal injury in mice following unilateral ureteral obstruction (UUO). We explored the time course of renal injury and Nrf2 expression in Nrf2+/+ mice following UUO. We compared Nrf2+/+ and Nrf2-/- mice following UUO in tubular damage, transdifferentiation [vimentin, proliferating cell nuclear antigen (PCNA)], fibrosis [fibronectin, α-smooth muscle actin (SMA)], antioxidative and inflammatory responses. We studied Nrf2 in renal biopsies of patients with acute, subacute and chronic tubulointerstitial nephritis (TIN). In Nrf2+/+ mice, renal Nrf2 expression and Nrf2-regulated glutamate-cysteine ligase catalytic (Gclc) and heme oxygenase-1 (Ho-1) were elevated, and renal injury occurred between 2 and 14 days after UUO. On Day 2 following UUO, in Nrf2-/- mice compared with Nrf2+/+ mice, tubular damage, apoptotic cell numbers, cleaved caspase3 and cleaved-poly ADP-ribose polymerase were increased. On Day 5, protein levels of vimentin and PCNA and the co-expressed cells of both proteins were increased. On Day 14, fibronectin and α-SMA protein levels were increased. Nrf2 deletion decreased expression of antioxidative genes (Gclc and Ho-1) and increased expression of inflammatory response genes (Tgfβ, Tnf, IL-6, IL-1β and F4/80). Finally, Nrf2 expression was upregulated in renal biopsies of patients with TIN. Following UUO, Nrf2 deficiency increased tubular damage, transdifferentiation, fibrosis and inflammatory response while decreasing antioxidative responses. The renal protective role of Nrf2 in the development of tubulointerstitial fibrosis in UUO may be mediated by antioxidative and anti-inflammatory pathways.

Dapagliflozin: Cardiovascular Safety and Benefits in Type 2 Diabetes Mellitus.

Sodium-glucose co-transporter 2 inhibitors (SGLT2is) such as dapagliflozin, canagliflozin, and empagliflozin, are a promising new therapy in the treatment of type 2 diabetes mellitus (T2DM). SGLT2is can effectively reduce hyperglycemia thus improving glycemic control and they offer some beneficial effects on the cardiovascular (CV) system which can benefit patients with heart failure in addition toT2DM. The United States Food and Drug Administration requires new diabetes mellitus therapies to show a CV safety profile. Empagliflozin was the first SGLT2i that, when added to the standard of care for patients withT2DM at high risk for CV events, showed improved CV outcomes including reduced deaths from CV causes. Evidence also exists in favor of dapagliflozin for use in patients with T2DM with CV risk factors and heart failure. This review focuses on the effects, safety, and benefits of dapagliflozin on the CV system. Clinical trials have shown that dapagliflozin improves glycemic control without variation. It is safe and well-tolerated in the general population including older patients and those with high-risk CV factors or preexisting CV disease. There may be a renal protective role by an unknown mechanism. Dapagliflozin also lowers blood pressure due to its natriuresis effect. It improves levels of visceral fat and reduces body weight, and thus ameliorates metabolic syndrome. Dapagliflozin reduces oxidative stress and may delay atherosclerosis. Recent findings indicate SGLT2is may also reduce the atrial natriuretic peptide levels. Additional trials are required to validate these benefits and further evaluate if these are class effects. Trials such as DECLARE-TIMI58 are ongoing to evaluate the CV outcomes of dapagliflozin. More research is needed to design better antihyperglycemic regimes with clinical benefits in addition to good glycemic control.